<!DOCTYPE html>
<html>
<head>
<script>
function runtest() {
    var iframe = document.getElementById("iframe");
    iframe.src = "javascript:'A'";
    iframe.scrollTop;
    iframe.src = "javascript:''";
}
</script>
</head>
<body onload="runtest()">
<iframe id="iframe" style="width:1px;height:1px;"></iframe>
</body>
</html>

